INVESTIGADORES
ROMEO Hernan Esteban
congresos y reuniones científicas
Título:
Polymerization-induced phase separation as a one-step strategy to self-assemble gold nanoparticles inside polystyrene/epoxy matrices
Autor/es:
HERNÁN E. ROMEO; ALEJANDRO VÍLCHEZ VILLALBA; JORDI ESQUENA MORET; CRISTINA E. HOPPE; ROBERTO J. J. WILLIAMS
Lugar:
Bahía Blanca
Reunión:
Simposio; Simposio Argentino de Polimeros; 2011
Resumen:
The rational design of nanoparticle (NP)/polymer composites with advanced functional properties is based on controlling the distribution and self-assembly of NPs in the polymer matrix (Pileni, 2005). Individual NPs are frequently functionalized with organic ligands which impart colloidal stability and enable their dispersion in a variety of polymer matrices. Depending on the self-organization of these NPs into mesoscopic structures (hcp, fcc, bcc, among others), different sets of physical properties can be finally obtained. In particular, the incorporation of such assemblies in chemically and mechanically stable solid substrates, like crosslinked epoxy polymers, opens novel and exciting ways for the development of materials for new technological applications. One approach to self-assemble NPs inside a crosslinked polymer is to produce a multiphase material where NPs can be preferentially segregated to one of the generated phases. In this work we report a simple one-step process for the encapsulation and self-assembly of alkanethiol-functionalized Au NPs inside microdomains of a linear polymer dispersed in an epoxy matrix. The idea was to employ a thermoplastic polymer (polystyrene, PS) as a modifier of the initial formulation which can phase separate in the course of the polymerization of the epoxy monomer. If the NPs, depending on the covering stabilizing organic molecules, have higher affinity for the PS than for the epoxy will be preferentially partitioned and confined inside the separated thermoplastic domains. This confinement would lead to the simultaneous self-assembly of the NPs as the polymerization takes place.